摘要
土壤退化已成为严重的全球性环境问题之一 ,全球共有 2 0亿hm2 的土壤资源受到土壤退化的影响 ,即全球农田、草场、森林与林地总面积大约 2 2 %的土壤发生了不同程度的退化。土壤侵蚀、化学退化、物理退化是全球范围内最主要的退化形式。土壤退化是人类活动诱导和加速的一种自然过程 ,其中最主要的人为驱动因素为农业土壤不适当的利用与管理、森林破坏以及过度放牧等。土壤退化的直接后果是导致土壤生产力的大幅度下降 ,在过去 5 0年中 ,由于土壤退化而导致的全球农业产量下降幅度为 11.9%～ 13.4 %。此外 ,土壤退化还造成如河流与湖泊淤积、土壤有机碳储量变化、特殊生境消失以及生物多样性减少等其它环境与生态问题 ,对人类的生存与可持续发展形成极大威胁。因此 ,为了确保粮食安全与维护生态环境健康 ,全球在不同尺度、不同水平上防治土壤退化、修复与重建退化土壤 。
Soil degradation, defined as lowing and losing of soil functions, is becoming more and more serious worldwide in the last decades, and exerts a thread to agricultural production and terrestrial ecosystem. It is estimated that nearly 2 billion hectares of soil resources of the world have been degraded, namely around 22 percent of all cropland, pasture, forest, and woodland. Globally, soil erosion, chemical deterioration and physical degradation are the important forms amongst various types of soil degradation. As a natural process, soil degradation can be enhanced or dampened by a variety of human activities such as inappropriate agricultural management, overgrazing and deforestation, etc. Degraded soil means less food. As a result of soil degradation, it is estimated that about 11.9 ～13.4 percent of the global agricultural supply has been lost in the past five decades. Besides, soil degradation is also associated with off site problems of sedimentation, climate change, watershed functions, and changes in natural habitats leading to loss of genetic stock and biodiversity. Therefore, it is quite essential to combat soil degradation at different levels and scales worldwide, not only for food security and ecological health, but also for guarantee of global sustainable development.
出处
《地球科学进展》
CAS
CSCD
2002年第5期720-728,共9页
Advances in Earth Science
基金
中国科学院区域开发前期研究项目"太湖流域经济发展对水环境影响研究"(编号 :区域Ⅳ 990 5)
国家重点基础研究发展规划项目"首都北京及周边地区大气
水
土环境污染机理与调控原理"(编号:G19990 45 707)资助
